ArticlePDF Available

Peak Phosphorus: Clarifying the Key Issues of a Vigorous Debate about Long-Term Phosphorus Security

DOI:10.3390/su3102027
Authors:
Dana Cordell at University of Technology Sydney
Dana Cordell
Stuart Bruce White at University of Technology Sydney
Stuart Bruce White
Download full-text PDFDownload full-text PDF
Read full-text
Download citation

Abstract and Figures

This paper reviews the latest information and perspectives on global phosphorus scarcity. Phosphorus is essential for food production and modern agriculture currently sources phosphorus fertilizers from finite phosphate rock. The 2008 food and phosphate fertilizer price spikes triggered increased concerns regarding the depletion timeline of phosphate rock reserves. While estimates range from 30 to 300 years and are shrouded by lack of publicly available data and substantial uncertainty, there is a general consensus that the quality and accessibility of remaining reserves are decreasing and costs will increase. This paper clarifies common sources of misunderstandings about phosphorus scarcity and identifies areas of consensus. It then asks, despite some persistent uncertainty, what would it take to achieve global phosphorus security? What would a ‘hard-landing’ response look like and how could preferred ‘soft-landing’ responses be achieved?
Figures - uploaded by Dana Cordell
Author content
All figure content in this area was uploaded by Dana Cordell
Content may be subject to copyright.
02bfe50e3a95a497130000
00.pdf
Content uploaded by Dana Cordell
Author content
All content in this area was uploaded by Dana Cordell
Content may be subject to copyright.
Peak Phosphorus: Clarifying the Key Issues of a Vigorous Debate about Long-Term Phosphorus Securi
ty.pdf
Available via license: CC BY 4.0
Content may be subject to copyright.
A preview of the PDF is not available
... The demand for P fertilizers, however, is expected to increase in the next decades; the global peak in P production has been predicted to occur around 2030 [14]. Estimates of when existing P reserves could be exhausted, however, range widely from the next 40-400 years [15,57], US [88]. The exact timing of peak P production is disputed, but the quality of the remaining phosphate rock is widely acknowledged to be continuously decreasing [18,36], so production costs are increasing and thus hindering the access of lowincome countries to P fertilizers. ...
... This unequal distribution and the unequal economic capacity of different countries has caused large surpluses in most of eastern Asia, western and southern Europe, the coastal USA and southern Brazil but deficits in Africa [52,89]. Over-fertilized soils are frequently saturated with P because of their historically high applications [15,60]. P deficits occur across 30% of the world's cropland area, and prolonged P deficits can deplete soil P and limit crop yields [52]. ...
... The low-income and food-deficient countries in sub-Saharan Africa, central Asia and Latin America generally suffer from low P inputs (0-5 kg ha −1 ) to their systems of agricultural production. P scarcity is thus seriously threatening soil fertility, agricultural production and global food security in several areas [15,100]. ...
A better use of fertilizers is needed for global food security and environmental sustainability
Article
Full-text available
  • Mar 2023
The massive use of fertilizers during the last decades allowed a great increase in the global capacity of food production. However, in the last years, several studies highlight the inefficiency and country asymmetries in the use of these fertilizers that generated environmental problems, soil nutritional imbalances and not optimal food production. We have aimed to summarize this information and identify and disentangle the key caveats that should be solved. Inadequate global management of fertilization produces areas with serious nutrient deficits in croplands linked with insufficient access to fertilizers that clearly limit food production, and areas that are overfertilized with the consequent problems of environmental pollution affecting human health. A more efficient use of nitrogen (N), phosphorus (P) and potassium (K) fertilizers for food security while preserving the environment is thus needed. Nutrient imbalances, particularly the disequilibrium of the N:P ratio due to the unbalanced release of N and P from anthropogenic activities, mainly by crop fertilization and expanding N-fixing crops that have continuously increased the soil N:P ratio, is another issue to resolve. This imbalance has already affected several terrestrial and aquatic ecosystems, altering their species composition and functionality and threatening global biodiversity. The different economic and geopolitical traits of these three main macronutrient fertilizers must be considered. P has the fewest reserves, depending mostly on mineable efforts, with most of the reserves concentrated in very few countries (85% in Morocco). This problem is a great concern for the current and near-future access to P for low-income countries. N is instead readily available due to the well-established and relatively low-cost Haber–Bosch synthesis of ammonium from atmospheric N2, which is increasingly used, even in some low-income countries producing an increasing imbalance in nutrient ratios with the application of P and K fertilizers. The anthropogenic inputs of these three macronutrients to the environment have reached the levels of the natural fluxes, thereby substantially altering their global cycles. The case of the excess of N fertilization is especially paradigmatic in several areas of the world, where continental water sources have become useless due to the higher nitrate concentrations. The management of N, P and K fertilizers is thus in the center of the main dichotomy between food security and environmentally driven problems, such as climate change or eutrophication/pollution. Such a key role demands new legislation for adopting the well-known and common-sense 4R principle (right nutrient source at the right rate, right time and right place) that would help to ensure the appropriate use of nutrient resources and the optimization of productivity.
View
... Other researchers have argued that new tools to optimize microbiological processes are needed to improve soil fertility [38]. This is relevant because there are also concerns about the decline in global phosphorus supplies associated with reaching peak phosphorus mining reserves [39,40]. Weight of the straw , g m -2 Figure 6. ...
... Other researchers have argued that new tools to optimize microbiological processes are needed to improve soil fertility [38]. This is relevant because there are also concerns about the decline in global phosphorus supplies associated with reaching peak phosphorus mining reserves [39,40]. ...
The Influence of Bacteria-Inoculated Mineral Fertilizer on the Productivity and Profitability of Spring Barley Cultivation
Article
Full-text available
  • Mar 2023
The heavy use of mineral fertilizers causes imbalances in the biological processes that take place in soil. Therefore, it is necessary to develop more effective fertilizers or fertilizer complexes that ensure agricultural productivity and soil conservation. There is currently a lack of knowledge regarding the effectiveness of biologically enriched, complex mineral fertilizers for spring barley fertilization. The hypothesis of this study was that bacteria-enriched (Paenibacillus azotofixans, Bacillus megaterium, Bacillus mucilaginosus, and Bacillus mycoides), complex mineral fertilizers (N5P20.5K36) have significant impacts on the yield and potential for economic use of spring barley. Experimental studies were carried out for three years (2020–2022) with sandy loam soil in southern Lithuania. Four different spring barley fertilization scenarios (SCs) were investigated. In SC-1 (control), complex mineral fertilizer (N5P20.5K36) was not applied. In the other SCs, spring barley was sown with a drill and fertilizers were incorporated locally during the sowing operation: fertilization scenario SC-2 used 300 kg ha−1, SC-3 used 150 kg ha−1 preceded by a bacteria-inoculated complex mineral fertilizer (N5P20.5K36), and SC-4 used 300 kg ha−1 with the same bacterial complex. The results showed that the bacterial inoculant increased the efficiency of the mineral fertilizer and had an effect on plant growth in barley. For three consecutive years in the same plots, the bacterial inoculant showed significant positive effects on grain yield (changes of 8.1% in 2020, 6.8% in 2021, and 17.3% in 2022 between SC-2 and SC-4). Comparing the several different fertilizer scenarios from an economic point of view, it was observed that the highest profit per hectare was obtained with SC-4 in all three years of the study. Comparing SC-4 and SC-2, an increase of 13.7% was observed in 2020, followed by 9.1% and 41.9% in 2021 and in 2022, respectively. This study will be useful for farmers, biological inoculant manufacturers, and scientists researching the effectiveness of biological inoculants for growing agricultural crops. We found that it is possible to increase the yield of barley (7–17%) using the same rate of mineral fertilization by enriching it with bacterial inoculants. Further studies should be conducted to determine the effects of the bacterial inoculant on crop yield and soil over a period longer than 3 years.
View
... Historically, over 90% of mined and processed P was used in agriculture as fertilizer or feed Scholz et al., 2013) and the remaining P is applied in other industries, such as detergent production. To date, around two-thirds of the world's agricultural soils are phosphorus-deficient (Cordell and White, 2011). ...
Measuring anthropogenic phosphorus cycles to promote resource recovery and circularity in Morocco
Article
Phosphorus (P) is essential for plant growth and food production. We examine anthropogenic phosphorus use in Morocco for the year 2018. Results show that a total of 11,654 kt P was extracted in 2018, of which 82.14% was exported and the remaining 17.86% was applied in the local industries and stored as reserves. The most considerable P loss to the environment came from the mining and manufacturing stages (494 kt P/y). In 2018, 90% of the total P waste originated from mining and manufacturing stages and the recovery rate was 55% (727 kt P/y), mainly from mining waste disposal facilities. The remaining waste was dumped into the environment (603 kt P/y) due to the lack of efficient P recovery technologies. Consequently, it is crucial to enhance P recovery and recycling so that future phosphorus resource circularity can be improved.
View
... Les principaux gisements se situent aux États-Unis, en Chine, au et al., 2022). Ces ressources sont cependant amenées à diminuer, le pic de production mondiale de phosphore minéral étant par exemple estimé pour 2035 (Cordell and White, 2011;Li et al., 2019). Le prix de ces ressources est en constante hausse du fait de l'augmentation de la demande notamment dans les pays en pleine révolution agricole, comme la Chine et l'Inde (Lecuyer et al., 2013). ...
Rôle des infrastructures et des pratiques agroécologiques pour la conservation de la biodiversité dans les systèmes de grandes cultures en Camargue
Thesis
Full-text available
  • Oct 2022
Résumé : L’intensification de l’agriculture est une menace majeure pour la biodiversité. L’homogénéisation des paysages et les changements de pratiques réduisent la quantité et la qualité des habitats disponibles. Dans ce contexte, l’écologie des paysages peut être utilisée dans le but de proposer des modes de gestion agroécologique favorables à la biodiversité. Dans cette thèse j’ai étudié les effets des interactions entre les bordures de parcelles et les pratiques agricoles ainsi qu’entre les bordures de parcelles et les milieux semi-naturels. J’ai pris pour modèle d’étude les paysages rizicoles du delta du Rhône en Camargue. Les paysages camarguais se caractérisent par de grands espaces de zones humides protégés en réserve, des zones de pâturage extensif et de marais à vocation cynégétique et des parcelles de grande culture. Selon leur localisation, ces cultures sont entourées de milieux semi-naturels ou dans des paysages d’openfields. En tant que zone humide majeure du bassin méditerranéen, il existe dans le delta du Rhône des enjeux de conservation de la biodiversité très importants. La Camargue est donc une zone d’étude intéressante pour travailler sur des modes de gestion agroécologique qui permettent de concilier la production alimentaire et la conservation de la biodiversité. En étudiant l’effet de l’hétérogénéité du paysage le long d’un gradient d’intensité d’utilisation de pesticides, je montre que la présence de milieux semi-naturels surfaciques et de bordures de parcelles a un effet positif plus important pour la biodiversité dans les paysages agricoles intensifs. Ces milieux sont utilisés comme des zones refuges par différentes espèces. J’ai ensuite étudié l’effet des surfaces de bordures de parcelles le long d’un gradient de surface de milieux semi-naturels dans des paysages en agriculture biologique. J’ai ainsi mis en évidence le rôle d’habitat de substitution que peuvent avoir les bordures de parcelles pour les oiseaux nicheurs ainsi que leur utilisation comme habitat complémentaire pour les oiseaux hivernants. Cependant, la diversité des niches des espèces rencontrées dans les milieux agricoles camarguais induit des réponses contrastées aux variations de la quantité des différents types d’infrastructures agroécologiques. Afin de prendre en compte ces variations, j’ai modélisé l’effet de la plantation de haies dans le but d’optimiser la conservation de la biodiversité et la fourniture de services écosystémiques. En conclusion, l’intensification agricole est une menace majeure pour la biodiversité, mais l’adoption de pratiques agroécologiques peut permettre de réduire ces impacts et même offrir des milieux favorables aux espèces. La prise en compte des milieux agricoles dans les programmes de conservation de la biodiversité en Europe est donc nécessaire. Abstract: Agricultural intensification is a major threat to biodiversity. The homogenization of landscapes and the changes of practices reduce the quantity and quality of available habitats. In this context, landscape ecology can be used to propose agroecological management methods that are favorable to biodiversity. In this thesis, I studied the effects of interactions between field margins and agricultural practices and between field margins and semi-natural habitats. I used the rice paddy landscapes of the Rhone delta in the Camargue as a study model. The Camargue landscapes are characterized by large protected areas (wetlands mostly), extensive grazing areas and marshes for hunting purposes and crop fields surrounded by semi-natural habitats or, on the contrary, in open fields. Depending on their location, these crops are surrounded by semi-natural habitats or, on the contrary, in open fields. As a major wetland area of the Mediterranean basin, the Rhône delta has very important biodiversity conservation issues. The Camargue is therefore an interesting study area for working on agroecological management methods that reconcile food production and biodiversity conservation. By studying the effect of landscape heterogeneity along a gradient of pesticide use intensity, I show that the presence of semi-natural habitats and field margins has a greater positive effect on biodiversity in intensive agricultural landscapes. These habitats are used as refuges by different species. I then studied the effect of field margins area along a gradient of semi-natural habitat surfaces in organic farming landscapes. I highlighted the role of field margins as substitute habitat for breeding birds and their use as complementary habitat for wintering birds. However, the diversity of niches of species found in the agricultural landscapes of the Camargue induces contrasting responses to variations in the quantity of the different types of agroecological infrastructure. In order to take these variations into account, I modeled the effect of hedgerow planting in order to optimize biodiversity conservation and the provision of ecosystem services. In conclusion, agricultural intensification is a major threat to biodiversity, but the adoption of agroecological practices can reduce these impacts and even provide favorable habitats for species. It is therefore necessary to take into account agricultural landscapes in biodiversity conservation programs in Europe.
View
... Phosphorus (P), along with nitrogen (N) and potassium (K), is an essential nutrient in food production systems. Nowadays, P is mostly obtained from mined phosphate rock, which is a finite resource unevenly distributed around the world, so uncertainties may arise about supply [1]. The European Union (EU) has identified phosphate rock and P as two of the 27 critical raw materials of great importance to the EU economy and with a high risk associated with their supply [2]. ...
Second-Generation Magnesium Phosphates as Water Extractant Agents in Forward Osmosis and Subsequent Use in Hydroponics
Article
Full-text available
  • Feb 2023
The recovery of nutrients from wastewater streams for their later use in agricultural fertilization is an interesting approach. Wastewater recovered magnesium phosphate (MgP) salts were used in a forward osmosis (FO) system as draw solution in order to extract water and to produce a nutrient solution to be used in a hydroponic system with lettuces (Lactuca sativa, L.). Owing to the low solubility of the MgP salts (i.e., struvite, hazenite and cattiite) in water, acid dissolution was successfully tested using citric and nitric acids to reach pH 3.0. The dilution by FO of the dissolved salts reached levels close to those needed by a hydroponic culture. Ion migration through the membrane was medium to high, and although it did not limit the dilution potential of the system, it might decrease the overall feasibility of the FO process. Functional growth of the lettuces in the hydroponic system was achieved with the three MgP salts using the recovered water as nutrient solution, once properly supplemented with nutrients with the desired concentrations. This is an innovative approach for promoting water reuse in hydroponics that benefits from the use of precipitated MgP salts as a nutrient source.
View
... Even more importantly, Abelson [15] identified a potential phosphorus crisis because global rock P reserves are being depleted and predicted that future generations will ultimately face problems in obtaining enough P to exist. One projection is that rock phosphate production will peak in 2033 at a volume approaching 30 million tonnes [16], although other projections suggest that peak phosphorus will occur decades later [17]. Nevertheless, global rock P reserves are finite, hence the potential crisis. ...
The Contribution of Phytate-Degrading Enzymes to Chicken-Meat Production
Article
Full-text available
  • Feb 2023
The contribution that exogenous phytases have made towards sustainable chicken-meat production over the past two decades has been unequivocally immense. Initially, their acceptance by the global industry was negligible, but today, exogenous phytases are routine additions to broiler diets, very often at elevated inclusion levels. The genesis of this remarkable development is based on the capacity of phytases to enhance phosphorus (P) utilization, thereby reducing P excretion. This was amplified by an expanding appreciation of the powerful anti-nutritive properties of the substrate, phytate (myo-inositol hexaphosphate; IP6), which is invariably present in all plant-sourced feedstuffs and practical broiler diets. The surprisingly broad spectra of anti-nutritive properties harbored by dietary phytate are counteracted by exogenous phytases via the hydrolysis of phytate and the positive consequences of phytate degradation. Phytases enhance the utilization of minerals, including phosphorus, sodium, and calcium, the protein digestion, and the intestinal uptakes of amino acids and glucose to varying extents. The liberation of phytate-bound phosphorus (P) by phytase is fundamental; however, the impacts of phytase on protein digestion, the intestinal uptakes of amino acids, and the apparent amino acid digestibility coefficients are intriguing and important. Numerous factors are involved, but it appears that phytases have positive impacts on the initiation of protein digestion by pepsin. This extends to promoting the intestinal uptakes of amino acids stemming from the enhanced uptakes of monomeric amino acids via Na+-dependent transporters and, arguably more importantly, from the enhanced uptakes of oligopeptides via PepT-1, which is functionally dependent on the Na+/H+ exchanger, NHE. Our comprehension of the phytate–phytase axis in poultry nutrition has expanded over the past 30 years; this has promoted the extraordinary surge in acceptance of exogenous phytases, coupled with the development of more efficacious preparations in combination with the deflating inclusion costs for exogenous phytases. The purpose of this paper is to review the progress that has been made with phytate-degrading enzymes since their introduction in 1991 and the underlying mechanisms driving their positive contribution to chicken-meat production now and into the future.
View
... As of 2022, India consumes about 7.5 Mt 25 of P (The Fertilizer Association of India, 2022), and the overall fertilizer import is 26 estimated at Seven Billion USD (Gowd et al., 2021). P is one of the rare-earth 27 elements, which is projected to last for the next 80 years (Cordell and White, 2011). 28 P is widely used in industries as fertilizers, flame retardants, batteries, steel 29 production, catalysis, and feed phosphates. ...
Nutrient recovery from wastewater in India: A perspective from mass and energy balance for a sustainable circular economy
Preprint
Full-text available
  • Feb 2022
Limited global phosphorus availability and increased eutrophication due to discharge of nitrogen pushed everyone to rethink the way, on how to recover nutrients. Wastewater is a potential source to recover N and P, while in India, it is scarcely explored. Understanding nutrient recovery systems involve exploring individual unit operations, sizing, and their energy consumption. Most studies on nutrient recovery from wastewater have focussed on retrieving, while least studies focused on mass and energy balance, which holds the key for its application potential. In this work, four different nutrient recovery system was compared, when added to an STP plant for a mid-size city in India. The results indicate that fuel cells consume the lowest energy at 216.2 kWh/1000m3, while microalgae used the highest energy at 943.3 kWh/1000m3. However, from a cost point of view except microalgae (78.6$/1000 m3) other nutrient systems did not yield any savings.
View
Leitfaden RessourcenPlan – Teil 3.3: Maßnahmen des Quartiersmanagements: Maßnahmensteckbriefe. Ergebnisse des Projekts R2Q RessourcenPlan im Quartier
Technical Report
Full-text available
  • Feb 2023
Der "Leitfaden RessourcenPlan" dient der anwendergerechten Darstellung der Ergebnisse des BMBF-Projekts "RessourcenPlan im Quartier (R2Q)". In Teil 3 werden Anwendungs- und Planungshilfen für die Etablierung des RessourcenPlans in anderen Kommunen bereitgestellt.
View
View
GRISAAS an Edited Book-2023
Book
Full-text available
  • Feb 2023
View
Checklist of Peak Experiences Challenging Humanity
Article
Full-text available
  • Aug 2008
The challenge of peak oil has been widely discussed and documented -- namely as the point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. The following checklist offers some pointers to other "peaks" by which humanity may be challenged. Of course these "peaks" do not reflect independent phenomena but interact to exacerbate with one another, reducing the time before any one of them is encountered.
View
View
Reconsideration of the Planetary Boundary for Phosphorus
Article
Full-text available
Phosphorus (P) is a critical factor for food production, yet surface freshwaters and some coastal waters are highly sensitive to eutrophication by excess P. A planetary boundary, or upper tolerable limit, for P discharge to the oceans is thought to be ten times the pre-industrial rate, or more than three times the current rate. However this boundary does not take account of freshwater eutrophication. We analyzed the global P cycle to estimate planetary boundaries for freshwater eutrophication. Planetary boundaries were computed for the input of P to freshwaters, the input of P to terrestrial soil, and the mass of P in soil. Each boundary was computed for two water quality targets, 24 mg P m − 3, a typical target for lakes and reservoirs, and 160 mg m − 3, the approximate pre-industrial P concentration in the world's rivers. Planetary boundaries were also computed using three published estimates of current P flow to the sea. Current conditions exceed all planetary boundaries for P. Substantial differences between current conditions and planetary boundaries demonstrate the contrast between large amounts of P needed for food production and the high sensitivity of freshwaters to pollution by P runoff. At the same time, some regions of the world are P-deficient, and there are some indications that a global P shortage is possible in coming decades. More efficient recycling and retention of P within agricultural ecosystems could maintain or increase food production while reducing P pollution and improving water quality. Spatial heterogeneity in the global P cycle suggests that recycling of P in regions of excess and transfer of P to regions of deficiency could mitigate eutrophication, increase agricultural yield, and delay or avoid global P shortage.
View
View
View
View
Global oil production about to peak? A recurring myth
Article
  • Jan 2006
Time and again, rumor says that the world oil production is "peaking" yet until now, there is enough oil supply. Figures show that the world consumes 80 million barrels of oil a day and by 2030, world oil demand is estimated to grow by 50 percent, that is 121 million barrels a day. According to the International Energy Agency, there are sufficient oil resources to meet demand for at least the next 30 years. The key factor to realizing this need is through technology advances such as directional drilling, horizontal drilling and 3-D seismic technology. The U.S. Energy Information Administration projects that fossil fuels will continue to dominate U.S. energy consumption, with oil and natural gas providing almost two-thirds of that consumption in the year 2025.
View
View
View
Smil, V. Phosphorus in the environment: natural flows and human interferences. Annu. Rev. Energy Environ. 25, 53-88
Article
Phosphorus has a number of indispensable biochemical roles, but it does not have a rapid global cycle akin to the circulations of C or N. Natural mobilization of the element, a part of the grand geotectonic denudation-uplift cycle, is slow, and low solubility of phosphates and their rapid transformation to insoluble forms make the element commonly the growth-limiting nutrient, particularly in aquatic ecosystems. Human activities have intensified releases of P. By the year 2000 the global mobilization of the nutrient has roughly tripled compared to its natural flows: Increased soil erosion and runoff from fields, recycling of crop residues and manures, discharges of urban and industrial wastes, and above all, applications of inorganic fertilizers (15 million tonnes P/year) are the major causes of this increase. Global food production is now highly dependent on the continuing use of phosphates, which account for 50–60% of all P supply; although crops use the nutrient with relatively high efficiency, lost P that reaches water is commonly the main cause of eutrophication. This undesirable process affects fresh and ocean waters in many parts of the world. More efficient fertilization can lower nonpoint P losses. Although P in sewage can be effectively controlled, such measures are often not taken, and elevated P is common in treated wastewater whose N was lowered by denitrification. Long-term prospects of inorganic P supply and its environmental consequences remain a matter of concern.
View